''the cost of mining one bitcoin would be 100 times greater than now but only half as many bitcoins would be mined that year''

I think you're fundamentally wrong thinking in these terms.

I don't know what you mean but the statement above is 100% correct given the assumptions. If the price of BTC goes to $1.4 million, the technical and economic factors make the cost of mining one BTC gravitate towards a little under $1.4 million. Also, in 2025 exactly half as many BTC will be mined than in 2021.

Higher price of bitcoin =/= higher energy consumption

I didn't say that the higher price is the direct cause of the higher energy consumption.

What increases energy consumption is 'new' hash rate joining the network, and this happens because NEW miners are joining (or because old ones are increasing their power). NOT the other way around (higher price increases difficulty).

You didn't read my post carefully enough. That's precisely what will happen and as a result the cost of mining will go up if the price goes up.

BTC mining algorithm adjusts itself to 'print' new blocks at 10 min/ block rate. All the other factors don't matter. If it isn't profitable to mine, some miners will shut down their machines & vice versa.

I know that.

Eventually miners will have (even more) optimized machines,

The bottom line is that the higher the price of BTC, the higher the cost of mining it will be. This is by design because mining is a competitive industry. If mining one BTC is clearly cheaper than buying one off the market, more mining power will be dedicated to mining it, resulting in mining difficulty adjustments until the gap between the cost of mining one BTC and buying one off the market disappears. It's a moving target, of course, because the price of Bitcoin is rather volatile.

and renewable energies will play a huge role in the future.

That's a different issue altogether. The Bitcoin network is completely agnostic as to how the electricity needed for mining it is generated. It will always be mined using the cheapest electricity available. The availability of the cheapest electricity may in some cases be denied by a government banning a dirty form of power generation. In other cases it might not.

The practical reality is that Bitcoin mining will always be crowding out other uses for the same generating capacity to some degree. But, ironically, it could also incentivize the formation of capital for the development of cheap forms of renewable energy such as solar generated in locations where the transmission of that power to other consumers would be prohibitively expensive. The externalities of such development could enable costs to be brought down for solar power generation for all purposes.